TV chiefs are set for one of the year’s biggest ratings battles as they go head to head for 30 million viewers tonight.

And the fierce contest comes despite the rival channels giving each other their schedules early in a bid to avoid hit shows clashing.

The move is designed to stop rows similar to when the finals of BBC1’s Strictly Come Dancing and ITV1’s X Factor went head to head.

But as a result of shows being shifted, tonight is set to be a real treat for viewers, who will face huge big choices over which channel to tune in to.

The final episode of BBC’s Call the Midwife has been moved from 8pm to 8.30pm to avoid a clash with ITV1 soap Coronation Street.

And the return of the second series of BBC1’s Upstairs Downstairs has now been shunted to 9.30pm, where it goes against ITV1’s Dancing on Ice and Channel 4’s eagerly-awaited Golden Globe-winning series, the US drama Homeland.

Sunday night is seen as a key battleground for networks as the time most viewers are likely to be at home.

George Dixon, controller of Channel 4, said: “It’s the biggest night of the week. There are 30 million viewers available, which is more than any other night.”

Homeland stars Claire Danes as a CIA agent who believes an American Marine held captive by al-Qaeda has been turned by the enemy.

Dixon added: “It’s a very big show for us and we wanted to give it a big slot. But we also, as we often do, want to put on an alternative for viewers.”

BBC1 controller Danny Cohen said of the Sunday night showdown: “There’s a definite, embedded expectation from the audience that they should get some thing special before work and school on Monday.”